Question : DAG & CAS array configured but it's not failover

Dear All,

I have Two Exchange 2010 servers installed with Mailbox, HUB and CAS roles. DAG and CAS array are configured for both servers and databases.

Now I'm facing a problem if one of the servers fails, the outlook is disconnected and it's start asking for Password. Even if I keep outlook open for 1 hour, it's still asking for password. I have to close and reopen the outlook again or provide the password.

I need your help to solve this issue since I think the client should failover automatically.

Thanks

Answer : DAG & CAS array configured but it's not failover

When you did your CAS array you gave it a name (say array.domain.com) to what IP this name is resolvable to?

Since your CAS servers and your Mailbox servers are on the same servers then you cannot use Windows Load Balancing for your CAS so how did you load balance your CAS servers ? Do you have a hardware load balancer ?

Did you change the configuration of your databases to use the cas array name as their RpcClientAccessServer ? you can do this by running get-mailboxdatabase | set-mailboxdatabase -RpcClientAccessServer array.domain.com


In your scenario you basically have 2 options

option 1
1. Get a hardware load balancer to load balance your CAS servers
2. create in your dns a record where array.domain.com points to the NLB IP of your CAS server
3. set the RpcClientAccessServer of your mailbox databases to array.domain.com


Option 2
1. Create in your DNS a record where array.domain.com point to the IP of one of your CAS servers with a low ttl
2. set the RpcClientAccessServer of your mailbox databases to array.domain.com
3. when you have a failure change in the DNS the IP of array.domain.com to the IP of the CAS server not failing